With the continued development and availability of video recording/playback equipment, an interest in the conversion of images stored on filmstrips and slides into video signals has developed. Video sensors and related video processing electronics are known which convert silver halide images to video signals which can be stored and played back as desired. By storing a plurality of these images, the need for employing projectors, screens and large number of slides can be reduced to a single video tape cartridge that can be readily viewed with any video playback unit, or VCR, of the proper format and a television.
Such devices are useful first for the conversion of existing libraries of slides and filmstrips which may be very bulky as well as old and valuable. Also, given the high quality and resolution of 35 mm cameras, it is possible to capture still images of various objects in significantly higher quality than by using existing video cameras. Yet, when these images from either source are stored on video tape, they can be readily and conveniently viewed for commercial use, entertainment as well as educational purposes.
In order to convert filmstrips and slides into video signals, the silver halide image is properly illuminated and positioned directly in front of the video sensor which scans and converts the image before it. When it is desired to convert many such images comprising perhaps hundreds of separate frames, a mechanism is required that can present the strips and slides accurately, repeatedly, and readily before the sensor.
While apparatus is available for such conversion of filmstrips and slides into electronic signals for magnetic storage, the known devices may not be capable of handling both filmstrips and slides, and the means for presenting a plurality of frames in a single position for rapid focusing and imaging have left much to be desired. Devices for transporting and positioning film strips and slides are known for a variety of projection equipment which must also locate a frame, in this instance, between a source of illumination and a lens, for viewing.
One manner by which a filmstrip can be correctly and separately positioned is by employing a notch at regular intervals which allows the strip to stop in proper registry. U.S. Pat. No. 3,232,167, for instance, provides a sound scanning assembly for a filmstrip projector. The filmstrip provides a plurality of picture areas and associated sound recording areas therebetween. A like plurality of notches are cut in one of the longitudinal edges of the strip, each notch being associated with a single sound area. The notches provide that one sound recording will be presented with one picture and they also control the transport mechanism for the sound scanning mechanism. Thus, the notches are employed to open and close a switch which, in turn, allows a scanning drum to travel axially in relation to the filmstrip as it moves transversely thereacross.
U.S. Pat. No. 3,905,694 provides a slide projector. A slide train is employed for carrying a plurality of linked slides and the train carries a plurality of notches by which one of several lugs, manually driven, advance the slides into illumination and projection.
Despite the existence of such carriers for the projection of filmstrips and slides, there exists a need for an apparatus that allows for the movement and positioning of multiple frames in video processing equipment. Such equipment provides a video processor and requires that it be positioned automatically in separate planes for filmstrips and for slides.